Continuous television transmission reproduction and playback

Abstract

A receiver/recorder of television transmissions is disclosed which operates automatically on a stand-by basis to record continuously television transmissions from at least one channel onto a reusable large capacity recording medium such as a magnetooptic disk. The recording is accomplished without user intervention and the system includes an indexing for distinguishing a recent recording from an older recording which is partially overlapped by the recent recording.

We claim: 
     
       1. An apparatus for receiving and recording television transmissions, comprising: means for continuously recording television transmissions from at least one channel onto a random-access rewritable recording medium wherein said means for recording provides for a continuous recording of received television transmission;   means for reproducing said recorded television transmission;   means for detecting a complete filling of said recording medium and providing a first signal fed to a return means to return a recording head to the beginning of said medium in order to rewrite subsequent transmissions at the beginning of said medium while simultaneously erasing transmissions which were previously recorded and providing a complete filling indication signal;   means for periodically writing to said medium a code representing a filling of said medium wherein said code remains the same until a specified filling is completed and wherein said code is changed to a second value when the recording head is returned to the beginning of the medium;   indexing means responsive to said code wherein said indexing means is recorded on said medium for automatically distinguishing a first in time recorded transmission from a second in time recorded transmission.   
     
     
       2. The apparatus according to claim 1 further comprising a means for detecting said code and a means which, after an interruption, provides for continuation of recording following the last location containing said second code value found at the beginning of the medium. 
     
     
       3. The apparatus according to claim 1 further comprising a backup energy source and a means for detecting an interruption in a supply current and means, supplied by said backup energy source, for writing a code indicating where the recording has stopped. 
     
     
       4. The apparatus according to claim 1 including a recording head and a separate reading head. 
     
     
       5. The apparatus according to claim 1 comprising a means of control for simultaneously recording at least two television channels. 
     
     
       6. The apparatus according to claim 1 wherein said recording medium comprises at least one disk. 
     
     
       7. The apparatus according to claim 5 wherein said recording medium comprises at least two disks. 
     
     
       8. The apparatus according to claim 1 further including a clock for continuously recording date information simultaneous with said television transmissions. 
     
     
       9. The apparatus according to claim 8 further comprising a means of fast searching from said date information. 
     
     
       10. The apparatus according to claim 8 including a means for preventing erasure of preselected transmissions between two predetermined dates. 
     
     
       11. The apparatus according to claim 1 further comprising a means for detecting the presence of television transmissions and an element responsive to said means for detecting the presence of television transmissions to control recording of said transmissions. 
     
     
       12. The apparatus according to claim 11 wherein said means for detecting the presence of television transmissions includes a means for detecting the presence of absence of line-frequency signals. 
     
     
       13. The apparatus according to claim 1 wherein said code is a binary code. 
     
     
       14. The apparatus for recording data comprising: means for continuously recording said data onto a random access rewritable recording medium wherein said means for recording provides for continuous recording of received data;   means for periodically writing to said medium a code representing a filling of said medium wherein said code remains the same until a specified filling is completed and wherein said code is automatically changed to a second value when the recording head is returned to the beginning of the medium.   
     
     
       15. The apparatus according to claim 14 further comprising a means for detecting said code and a means which, after an interruption, provides for continuation of recording following the last location containing said second code value found at the beginning of said medium.